Vor, II.] SPURGE FAMILY. 371 
1. Euphorbia polygonifolia I,, Seaside or Knotweed Spurge. (Fig. 2307.) 
Euphorbia polygonifolia I,. Sp. Pl. 455. —1753- 
Annual, pale green, glabrous, stem branched 
from the base, the branches radiately spreading, 
prostrate, forked, wiry, 3/-8’ long. Leaves op- 
posite, oblong, linear-oblong or linear-lanceo- 
late, 3//-10’’ long, fleshy, obtuse, often mucronu- 
late, entire, obtuse or subcordate and somewhat 
oblique at the base, short-petioled; stipules an 
inconspicuous fringe of short bristles; inyo- 
lucres usually solitary in the axils, turbinate- 
campanulate, less than 1// long, with 4 colum- 
nar nearly naked glands shorter than the lobes; 
peduncles twice as long as the involucres; cap- 
sule globose-ovoid, 114//-2’’ long, nodding, 
minutely wrinkled; seeds ovoid, 114’’ long, 
somewhat flattened, ash-colored, very minutely 
pitted and spotted. 
In sand along the Atlantic coast, Rhode Island to 
Florida, and on the shores of the Great Lakes. 
July-Sept. 
2. Euphorbia petaloidea Engelm. 
White-flowered Spurge. (Fig. 2308.) 
Euphorbia petaloidea Engelm. Bot. Mex. Bound. 
Surv. 185. 1859. 
Annual, pale green, glabrous. Stem usually 
rather stout, erect, branched above, 6’-2° high; 
leaves opposite, linear, oblong or linear-lanceo- 
late, 5’’-1’ long, obtuse, usually flat, straight, 
entire, slender-petioled; stipules a fringe of 
setae; involucres solitary in the axils, oblong- 
campanulate, 1/f long, bearing 4 wineglass- 
shaped glands about as long as the lobes, each 
subtended by a white ovate or orbicular entire 
or undulate appendage; peduncles as long as the 
involucres; capsule globose-reniform, 1/’ long, 
seeds oblong-oyoid, nearly 1’’ long, ash-colored, 
minutely pitted, nearly terete. 
Iowa to Wyoming and Texas. July—Sept. 
3- Euphorbia Nuttallii (Engelm.) Small. , \ 
Prairie Spurge. (Fig. 2309.) \ 
Euphorbia petaloidea var. Nuttallii Engelm. Bot. 
Mex. Bound. Surv. 185. 1859. 
££. zygophylloides Boiss. Cent. Euph. to. 1860. 
Luphorbia arenaria Engelm. & Gray, Bost. Journ. 
Nat. Hist. 5: 260. 1847. Not Nutt. 1837. 
Annual, bright green, glabrous. Stem slender, 
erect or ascending, branched, 4’-2° high, the 
branches wiry, leaves mostly linear and mu- 
cronulate or truncate at the apex, often involute, 
obtuse or narrowed at the base, petioled, usually 
curved, the midvein prominent; stipules lanceo- 
late or subulate-lanceolate; involucres solitary in 
the axils, campanulate, less than 1/’ long, long- 
peduncled, bearing 4 saucer-shaped glands sub- 
tended by white entire oblong or ovate append- 
ages; seeds ovoid, 3/’ long, gray, 4-angled. 
Prairies, Kansas to Texas and Mexico. June-Sept. 
